MCTupleTool allows list of single-precision-float, bool and int branches

FYI @masmith @erodrigu @mramospe

See discussion at #4 (closed). See related (but no interdependency) merge request Phys!878 (merged), which implements the equivalent functionality for DecayTreeTuple

Tested with

from DecayTreeTuple.Configuration import *
from Configurables import DaVinci
DaVinci().TupleFile = 'DVntuple.root'
DaVinci().Simulation = True
DaVinci().DataType = '2016'
DaVinci().EvtMax    =  1000
DaVinci().PrintFreq =  100
from GaudiConf import IOHelper
IOHelper().inputFiles(['root://eoslhcb.cern.ch//eos/lhcb/grid/prod/lhcb/MC/2016/ALLSTREAMS.DST/00065692/0000/00065692_00000548_7.AllStreams.dst'])

from Configurables import MCDecayTreeTuple
FSR_electrons = ' {e+} {e-} {e+} {e-} '
mcdttW = MCDecayTreeTuple("mcdttW")
mcdttW.ToolList = []
mcdttW.Decay = '[W+ => ^mu+ ^nu_mu' + FSR_electrons + ']CC'
mcdttW.addBranches({
    "W": '^[W+ =>  mu+  nu_mu' + FSR_electrons + ']CC',
    "mu": '[W+ => ^mu+  nu_mu' + FSR_electrons + ']CC',
    "nu": '[W+ =>  mu+ ^nu_mu' + FSR_electrons + ']CC'
})

atool = mcdttW.W.addTupleTool("LoKi::Hybrid::MCTupleTool/LoKi_MC")
atool.IntVariables = {"ID": "MCID"}
atool.FloatVariables = {
    "ETA": "MCETA",
    "PT": "MCPT",
    "PHI": "MCPHI",
}

DaVinci().UserAlgorithms.append(mcdttW)